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Remove repeated points from a geometry

Source: R/ddbs_ops_unary.R
ddbs_remove_repeated_points.Rd

Removes duplicate consecutive vertices from geometries, optionally within a tolerance distance.

Usage

ddbs_remove_repeated_points(
  x,
  tolerance = 0,
  conn = NULL,
  name = NULL,
  mode = NULL,
  overwrite = FALSE,
  quiet = FALSE
)

Arguments

x

Input spatial data. Can be:

  • A duckspatial_df object (lazy spatial data frame via dbplyr)

  • An sf object

  • A tbl_lazy from dbplyr

  • A character string naming a table/view in conn

Data is returned from this object.

tolerance

A numeric value specifying the minimum distance between consecutive vertices. Vertices closer than this threshold are considered repeated and removed. Default is 0, which removes only exact duplicates.

conn

A connection object to a DuckDB database. If NULL, the function runs on a temporary DuckDB database.

name

A character string of length one specifying the name of the table, or a character string of length two specifying the schema and table names. If NULL (the default), no table is written and the result is returned as a duckspatial_df or sf object, depending on mode

mode

Character. Controls the return type. Options:

  • "duckspatial" (default): Lazy spatial data frame backed by dbplyr/DuckDB

  • "sf": Eagerly collected sf object (uses memory)

Can be set globally via ddbs_options(mode = "...") or per-function via this argument. Per-function overrides global setting.

overwrite

Boolean. whether to overwrite the existing table if it exists. Defaults to FALSE. This argument is ignored when name is NULL.

quiet

A logical value. If TRUE, suppresses any informational messages. Defaults to FALSE.

Value

Depends on the mode argument (or global preference set by ddbs_options):

  • duckspatial (default): A duckspatial_df (lazy spatial data frame) backed by dbplyr/DuckDB.

  • sf: An eagerly collected object in R memory, that will return the same data type as the sf equivalent (e.g. sf or units vector).

When name is provided, the result is also written as a table or view in DuckDB and the function returns TRUE (invisibly).

Examples

if (FALSE) { # \dontrun{
## load package
library(duckspatial)
library(sf)

## Create a polygon with repeated points
poly <- st_polygon(list(matrix(
  c(0, 0,
    1, 0,
    1, 0,  # repeated point
    1, 1,
    0, 1,
    0, 0),
  ncol = 2, byrow = TRUE
)))

poly_sf <- st_as_sf(st_sfc(poly))

## remove exact duplicate consecutive vertices
ddbs_remove_repeated_points(poly_sf)

## remove vertices within a tolerance of 1 unit
ddbs_remove_repeated_points(poly_sf, tolerance = 1)
} # }